Current mobile or computer devices use a variety of different navigation mechanisms. Some of these present a mousing surface for direct manipulation by a finger (or other part of the body), and work by producing images of the finger as it moves on the mousing surface, translating this finger movement to movement of a cursor (for example) on a screen. In this respect, a navigation device of this type works in a similar fashion to an optical mouse, and is referred to as an optical navigation device.
Great Britain Application Number 0908900.4 discloses an optical navigation device comprising a main housing element and an optical transmission element, wherein the optical transmission element comprises an alignment shaft which, when assembling the optical transmission element and the main housing element to a base, is operable to align the optical transmission element to the base.
However, it has become apparent that optical components generally are helped by an extreme accuracy on their alignment in order to improve their efficiency. Accurate positioning is even more critical for very small optical components or devices as further parameters such as dust and dimensional accuracy of supporting structure, such as a housing element or device should be considered. In an optical navigation device comprising an assembly wherein an optical device and a housing device are glued together or clipped together, there remains an imprecision with respect to the position of the optical device which is basically due to cleanliness of the coincident surfaces, how the glue is dispersed on the surface(s), a dimensional accuracy of manufacture of the relevant parts to be combined, etc.